murder clearance rates

The Marshall Project has an intriguing article on how often homicides are “cleared” – meaning that the police have closed the case by identifying a likely killer. The big fact is that American murder clearance rates have gone down. As the chart above shows, homicide clearance has dropped by about a third.

Why? The authors offer a few reasons. For example, gaps in clearance rates for Whites and Blacks have grown a little, explaining some of the decrease over time. Another reason is that police departments now often use DNA evidence and other tools that require testing, which leads to delays and dropped cases. There has also been a massive shift in resources from homicide investigation to drug enforcement.

Here’s my guess: Before, there was a remarkably low barrier for getting a murder conviction. One reads cases of juries convicting people based on a single witness. In modern times, we simply have higher standards, which means that fewer cases will be cleared.

Firstly, you have to wonder what the F*** was going on prior to 1985. What really happened was that detectives were pressed to close cases; it sure seems like they could care less before that.

In “GhettoSide: The Story of Murder in the US,” Jill Leovy points out some of the pressures on police departments to close cases. There was a high case load back in those days: NYC regularly recorded over 2000 murders per year not to mention all of the assaults and shootings which did not end up as murder. One of main impediments was the lack of complaining witnesses: witnesses were systematically intimidated.

There has been a focus on forensics, on police procedures at the crime scenes, and as stated the invention of biotechnology, e.g. DNA fingerprinting.

But, I think that the real reason was the organization of police departments.

They were as interested in looking good in the 1960s as now. The hypothesis does not involve a change in motivation but a change in the rules of the game about how things get reported or checked. And I’m not saying it is not a real decline, either. Diversion of police resources into the drug war or other activities is certainly a possibility. But the decline does not seem to be tracking the murder rate at all, which is part of why it seems suspect.